I really hate most of the music they have for wrestlers nowadays. They all sound very similar to me in terms of their production (most are recorded in the same studio with the same musicians so that would be why of course) but yeah, so much of this bland heavy rock music. I mean it's cool for some to have rock songs but yeah, very little variation nowadays.
For me they were really at their height in the late 80s and through the 90s with themes...Hogan, Warrior, HBK, Austin, The Rock, Mankind (the music entering the ring
http://www.youtube.com/watch?v=o6Dm52by2-o&feature=related then if he won he got a different music
http://www.youtube.com/watch?v=VIokuD0cw-Q&feature=related, both very Twin Peaks esq, beautiful!) Razor Ramon, Undertaker, Angle, Bret and Owen... even Big Boss Man and one that cracks me up everytime;
http://www.youtube.com/watch?v=taOFLVnAIgY
They're great themes which suit the gimmick of the wrestler so well and hugely memorable and catchy. I watch Raw every week and I don't remember how Miz's theme sounds after the "Aweeeeeeeesome" part at the beginning.
However does this make the Miz any less great? Nah, therefore I disagree with your point. Austin/The Rock/Hogan would have been huge regardless of their theme. My point is a little different and I'm saying WWE themes are pretty generic now and not nearly as memorable as they used to be.
To be honest I think WWE should give Jim Johnson a consulting role or something now because his compositions are not what they used to be. Get a new person in (or a team of people) to work on songs varying in style and maybe we'll get some classic themes again that really stand out next to each other.
Oh and a few people have slated Daniel Bryan's music thus far but I think it's great they're using something that isn't a standard rock/metal song, it puts him in a great lineage along with Ric Flair and Macho Man who both had "classical" themes but are two of the greatest wrestlers of all time.